Detergent compositions



tnnss Human United States Patent 3,461,074 Patented Aug. 12, 1969 ice 3 461 074 As set forth hereinbefore, about 22 to about 70 percent i of the detergent composition consists of a heat-dried mix- DETERGENT COMPOSITIONS Lawrence L. Schwalley, Whittier, Califl, assignor to United States Borax & Chemical Corporation, Los Angeles, Calif., a corporation of Nevada No Drawing. Filed Oct. 22, 1965, Ser. No. 502,558 Int. Cl. Cll'd 9/34, 7/36 U.S. Cl. 252-109 12 Claims ABSTRACT OF THE DISCLOSURE Detergent compositions especially useful for forming laundry tablets. The compositions are heterogeneous mixtures of a heat-dried mixture, a nonionic synthetic detergent and alkali metal polyphosphate high in Form I. The heat-dried portion contains additional alkali metal polyphosphate which is low in Form I and an anionic synthetic detergent or soap.

This invention relates to novel detergent compositions which are particularly useful for forming laundry tablets.

Detergent tablets have become increasingly popular within the last few years primarily because of the convenience in using them. One problem, however, which has been difiicult to overcome is control of the rate of dissolving the tablet in the washing solution. The present invention provides an improvement in detergent compositions useful for laundry tablets in which the tablets are readily formed, will dissolve at a controlled rate in the washing solution, and have excellent detergency properties.

It is, therefore, the principal object of this invention to provide novel detergent compositions useful for forming laundry tablets.

It is a further object of this invention to provide a process for producing said detergent compositions.

A still further object of this invention is to provide improved laundry tablets utilizing such improved detergent compositions.

Other objects will become apparent from the following disclosure.

This invention provides detergent compositions for forming laundry tablets comprising a heterogeneous mixture of (a) About 22 to about 70 percent by weight of a heat-dried mixture comprising about one part by weight of a low Form I alkali metal polyphosphate and about 0.3 to about one part by weight of a member of the group consisting of the anionic synthetic detergents and soaps;

(b) About 1 to about 12 percent by weight of a nonionic synthetic detergent; and

(c) About 18 to about 77 percent by weight of a high Form I alkali metal polyphosphate.

The invention also provides a process for producing said detergent compositions and improved laundry tablets utilizing said detergent compositions.

The novel detergent compositions of the present invention can be used to form improved detergent tablets, with excellent properties. Laundry washing tablets utilizing the detergent compositions of this invention are readily formed, will dissolve in the laundry washing solution at a preferred rate, have the desirable degree of hardness so as to stand up under packaging and handling conditions, and have excellent fabric washing properties. Thus, detergent tablets incorporating the detergent compositions of the present invention have excellent solubility and high soil removal efficiency in washing solutions. Also, they are readily formed and have exceptional integrity, without resorting to the use of binders or surface hydration such as by spraying with water vapor.

ture of alkali metal polyphosphate and an anionic synthetic detergent or soap. Preferably, the heat-dried portion represents about 35 to about 60 percent of the composition. The term heat-dried is to be understood as having the meaning generally understood in the detergent art, that is, the components are mixed together, generally as an aqueous slurry, and then either spraydried into particulate form or drum-dried followed by reduction of the product to the desired particle size.

The polyphosphates useful in the heat-dried compositions are the low Form I (or high Form II) content alkali metal polyphosphates such as the sodium, potassium and lithium tripolyphosphates. Sodium tripolyphosphate is the presently preferred phosphate and, when used to prepare the heat-dried portion of the composition, should be low in Form I, that is containing less than about 5% Of Form I Naspaow.

In the heat-dried portion of the composition, one can use any of the anionic synthetic detergents or soaps well known to the art. Particularly useful anionic synthetic detergents are the water-soluble salts of higher aliphatic and aromatic sulfuric acids such as the sodium salts of alkylbenzenesulfonic acids and long chain alkylsulfates. Specific examples of such suitable anionic synthetic detergents include sodium octyl-, nonyl-, dodecyl-, decyl-, and tetradecylbenzenesulfonates, sodium diisopropylnaphthalene sulfonate, sodium isopropylnaphthalene sulfate, long chain alkylsulfates such as sodium lauryl-and stearylsulfates, the mahogany and petroleum sulfonates, long chain alkyloxyethylene sulfates such as sodium or potassium laurylpolyoxyethylene sulfate, sodium la lrnonooxyethylene sulfate, sodium octadecylpolyoxyethylene sulfate and sodium cetylpolyoxyethylene sulfate, long chain alkylaryloxyethylene sulfates such as ammonium, sodium or potassium nonyl-, octyl-, and tridecylphenol monoand polyoxyethylene sulfates, long chain alkyl isethionates such as sodium oleic isethionate and sodium lauric isethionate, lower alkyl sulfates and sulfonates such as sodium sulfate derivatives of Z-ethylhexanol-l, sodium 2-ethyl-1-hexenyl sulfonate, sodium isooctyl sulfonate, and lower alkylesters of aliphatic sulfocarboxylic acids such as sodium diamylsulfosuccinate.

As for soaps which can be employed in the heatdried mixture, there can be enumerated the water-soluble salts of myristic, palmitic, stearic, behenic, oleic, lauric, abietic,

capric, caproic, ricinoleic and linoleic acds, hydrogenated and dehydrogenated abietic acids, and the surface active hydrolysis products of tallow, coconut oil, cottonseed oil, soybean oil, peanut oil, sesame, linseed oil, olive oil, corn oil, castor oil, and the like.

In the heat-dried mixture, the weight ratio of anionic synthetic detergent and/or soap to polyphosphate is from about 0.3 to about 1:1, with a preferred ratio in the range of from about 0.4 to 0.7: 1.

A small amount, such as up to about 0.2 part, of nonionic synthetic detergent can also be included in the heatdried portion, and is preferred for reducing sticking in tablet pressing.

The heat-dried component is readily prepared using procedures and apparatus well known to those skilled in the detergent art. For example, the ingredients are made up in the desired proportions as an aqueous slurry and then heat-dried, as for example, by spray-drying into particulate form or by drum-drying followed by reduction of the product to the desired particle size such as through a 16 mesh screen. The presently preferred heat-drying procedure is spray-drying and the preferred particle size is predominantly about 30 to about mesh, with not more than about 10% through 200 mesh. The resulting heat-dried material is a homogeneous mixture suitable for incorporation in the novel detergent compositions of this invention.

As stated above, the novel detergent compositions of this invention contain from about 1 to about 12 percent and preferably from about 3 to 9 percent, by weight of a nonionic synthetic detergent, preferably a liquid nonionic detergent. Typical examples of these include the ethylene oxide condensation products with alkylphenols, such as nonylphenol, octylphenol, and diamylphenol. Usually, the phenols are condensed with 6 to 20 or more moles of ethylene oxide. Other examples include esters of the sugar alcohols, such as sorbitan and mannitan, the polyethyleneoxy esters of tall oil acids, ethoxylated alkanols such as ethoxylated lauryl alcohol, ethylene oxidefatty acid condenstates, and propylene glycol-ethylene oxide condensates.

The detergent compositions also contain about 18 to about 77 percent by weight of non-hydrated powdered or granular alkali metal polyphosphate in addition to that in the heat-dried portion of the mixture. Preferably, the compositions contain from about 30 to about 64 percent by weight of sodium tripolyphosphate. The polyphosphate is powdered or granular with a particle size range of from about 16 to +200 mesh, preferably in the range of about 30 to +100 mesh. The following is a typical analysis of a sodium tripolyphosphate suitable for this portion of the composition.

A T C. (measured in glycerine-salt) 14.5 Wt. percent loss on ignition- At 150' C 0.05

At 500 C 0.08

Na/P-ratio 1.686 pH of- 1% solution 10.0 16% solution 9.4 Wt. percent- Pentasodium tripolyphosphate content 90.4 Tetrasodium pyrophosphate content 8.0 Sodium metaphosphate content 1.5 Sodium orthophosphate content 0.1

Screen analysis Wt. percent retained on US. sieve 1 Degree of temperature rise (Centigrade) by hydration test in glycerine-salt solution. A value of 14.5 is typical of a high Form I tripolyphosphate.

It is essential that the polyphosphate in this portion of the composition is high in Form I Na P O that is it should contain from about 20 to 40% or higher of Form I, the form which hydrates more rapidly. By using a high Form I polyphosphate, I have found that the resultant tablet dissolves readily at a preferred controlled rate.

In addition to the foregoing components it is to be understood that desirable additives, such as fillers, builders, optical brighteners, perfumes, coloring agents, bacteriostats, corrosion inhibitors, anti-redeposition agents, sequestering agents, etc., can also be included in the compositions of this invention to provide specific desirable properties for which they are designed. Examples of a few of these additives are sodium tetraborate, sodium sulfate, sodium carbonate, sodium metasilicate, sodium carboxymethyl cellulose, ethylenediamine tetraacetic acid, fluorescent or optical pigments, talc, trichlorocarbanilide, hexachlorophene, trichlorosalicylanilide, etc. These additives can be incorporated in the heat-dried portion prior to heat-drying or they can be added to the composition during the preparation of the final heterogeneous mixture.

. .The novel detergent compositions of this invention are readily prepared merely by intimately mixing the components, such as at about room temperature, in suitable mixing or blending apparatus, in such proportions as to give a final product having the desired percentage of each component. The resulting product is a heterogeneous mixture of the components, which is especially useful for compression into laundry tablets.

Preferably, a portion of the nonionic detergent is added first to the heat-dried portion and the mixture allowed to cure before combining with the additional polyphosphate and remaining nonionic. Curing requires merely standing with slight agitation or tumbling in a slowly rotating mixer so as to allow the heat-dried portion to absorb the wet nonionic. Alternatively, curing usually is not required if a portion of the additional polyphosphate is added immediately in order to thereby coat the wet particles.

The following examples are presented to illustrate specific formulations of this invention, but it is to be understood that the invention is not limited to the specific examples given.

Example I The following materials were combined as a slurry in water and then spray-dried to give a granular detergent composition as follows:

Percent Sodium dodecylbenzene sulfonate 29 Sodium sulfate 7 Tetrasodium pyrophosphate 25 Pentasodium tripolyphosphate (about 5% Form I)--- 25 Sodium metalsilicate 12 Tetrasodium ethylenediarninetetraacetate N 2 The percentages are on a dry weight basis and the composition had less than 1% moisture and volatiles. The parparticles were -30 mesh size.

The above composition (39.93 parts by weight), which is referred to as Part I, was combined with 1.8 parts by weight of nonoylphenoxypoly(ethyleneoxy)ethanol and the mixture cured by intimately mixing in a slowly rotating drum for up to about 72 hours. The cured mixture was then blended with the following ingredients (referred to as Part Ii) in which said parts are by weight.

Parts Pentasodium tripolyphosphate (about 34% Form Nonylphenoxypoly(ethyleneoxy)ethanol 4.20 Sodium carboxymethyl cellulose (65% active) 2.50 Optical brightener a- 0.12 Perfume M 0.05

When pressed into tablets, the detergent composition had excellent tablet forming properties, dissolved completely in three minutes, and had outstanding clothes washing efficiency.

Example H Part I (spray-dried composition) was prepared as described in Example I and 39.39 parts were intimately mixed with 1.80 parts of nonylphenoxypoly(ethylenoxy) ethanol. Powdered high Form I pentasodium tripolyphosphate (5.0 parts) was then added to the mixture, thereby coating the particles coated with the nonionic detergent. The resultant mixture was then blended with Part II, hav- The resultant detergent formulation can be used to form excellent laundry washing tablets.

The detergent compositions can be used to form laundry tablets according to procedures well known to the art. Multipurpose laundry tablets containing a bleach core can be prepared by procedures described in Speak et al. U.S. Patent No. 3,154,494. For example, the bleach material is first compacted and then coated with the detergent composition. If desired, the coating can be preformed in two separate halves, each having a cavity therein, the bleach can be compressed to the desired shape and then deposited in the cavity formed in one half of the coating and the other half of the preformed coating can be pressed on top, forming a finished composition having a core of bleach and a coating contiguous therewith and completely enclosing the same. Another method of makig the tablet is to form one half of the coating with a cavity, fill the cavity with bleach powder, put the rest of the coating material on top and then press the entire mass to the desired shape. When the detergent composition is used to make a multipurpose tablet with a bleach core, it should be substantially dry, that is it should have a maximum of about 2% moisture and volatile matter. As pointed out above, the compositions can also be used to produce the usual single layer detergent tablets without a bleach core.

Thus, what has been provided is a superior detergent formulation for laundry detergent tablets containing alkali metal polyphosphate, anionic detergent (including soap), and nonionic detergent, in which the anionic detergent has been combined with a portion of of the alkali metal polyphosphate and a heat dried mixture formed, which is then combined with the nonionic detergent and the remaining alkali metal polyphosphate, which must be a high Form I polyphosphate.

Various changes and modifications of the invention can be made and, to the extent that such variations incorporate the spirit of this invention, they are intended to be included within the scope of the appended claims.

I, therefore, claim as my invention:

1. The process for producing a detergent composition suitable for forming laundry tablets which comprises (a) forming an aqueous slurry containing about one part by weight of a low Form I alkali metal polyphosphate containing less than about 5% Form I and about 0.3 to one part by weight of a member of the group consisting of the sulfonate and sulfate anionic synthetic detergents and water-soluble salts of higher fatty acid soaps, (b) heat-drying said slurry to form a homogeneous mixture, and (c) intimately mixing said homogeneous mixture with a liquid nonionic detergent and additional alkali metal polyphosphate containing at least about Form I in such proportions as to provide a heterogeneous mixture containing about 22 to 70 percent by weight of said homogeneous mixture, about 1 to 12 percent by weight of said liquid nonionic detergent and about 18 to about 77 percent by weight of said additional alkali metal polyphosphate. 2. The process according to claim 1 in which said alkali metal polyphosphate is sodium tripolyphosphate.

3. The process according to claim 1 in which said slurry is spray-dried.

4. The process for producing a detergent composition suitable for forming laundry tablets which comprises (a) forming an aqueous slurry containing about one part by weight of a low Form I alkali metal polyphosphate containing less than about 5% Form I and from about 0.4 to about 0.7 part by weight of a member of the group consisting of the sulfonate and sulfate anionic synthetic detergents and water-soluble salts of higher fatty acid soaps,

(b) heat-trying said slurry to form a homogeneous mixture, and

(c) intimately mixing said homogeneous mixture with a liquid nonionic detergent and additional alkali metal polyphosphate containing at least about 20% Form I in such proportions as to provide a heterogeneous mixture containing about 35 to about percent by weight of said homogeneous mixture, about 3 to about 9 percent by weight of said liquid nonionic detergent and about 30 to about 64 percent by weight of said additional alkali metal polyphosphate.

5. The process according to claim 4 in which said alkali metal polyphosphate is sodium tripolyphosphate.

6. The process according to claim 4 in which said alkali metal polyphosphate in the heat-dried homogeneous mixture is sodium tripolyphosphate containing less than about 5% of Form I Na P O and said additional alkali metal polyphosphate is sodium tripolyphosphate containing at least about 20% of Form I Na P O 7. The process according to claim 4 in which said slurry is spray-dried.

8. The process according to claim 4 wherein a portion of the nonionic detergent is added to the heat-dried homogeneous mixture and the resultant mixture allowed to cure prior to adding the remaining nonionic detergent and additional alkali metal polyphosphate.

9. In the process for producing detergent compositions containing alkali metal polyphosphate, anionic detergent and liquid nonionic detergent for laundry detergent tablets, the improvement which comprises forming a heatdried mixture of sulfonate or sulfate anionic detergent and a portion of said alkali metal polyphosphate and then combining the heat-dried mixture with said liquid nonionic detergent and the remaining portion of said alkali metal polyphosphate, said portion of alkali metal polyphosphate in the heat-dried mixture containing less than about 5% Form I polyphosphate and said remaining portion of said alkali metal polyphosphate containing at least about 20% Form I.

10. The process according to claim 4 in which a small amount of liquid nonionic detergent is added to said aqueous slurry prior to heat-drying said slurry.

11. A detergent composition produced in accordance with the process of claim 1.

12. A detergent composition produced in accordance with the process of claim 4.

References Cited UNITED STATES PATENTS 2,961,409 11/1960 Martin 252-l09 2,961,410 11/1960 Martin 252-109 2,622,068 12/1952 Hizer a- 252-138 3,081,267 3/1963 Laskey 252-435 3,154,494 10/1964 Speak et al. 252-96 LEON D. ROSDOL, Primary Examiner B. BETI'IS, Assistant Examiner U.S. Cl. XR. 

